Conventionally, as a connector for piping connection, one according to Japanese Laid-Open Patent Publication No. 2002-237346 has been known. According to this connector, a retainer for preventing detachment of a pipe is attached to a connector body via a pivot shaft such that it can pivot in a direction normal to an axial direction of the pipe. In particular, the pivot shaft is formed on an outer surface of the connector body along its axial direction, whereas a bearing portion for pivotally supporting the pivot shaft is formed on an end portion of the retainer. An opening for fitting therein the pivot shaft is expandably formed with the bearing portion. In attachment of the retainer, the pivot shaft can be fitted into the bearing portion by putting the pivot shaft at the opening and forcibly pressing the pivot shaft from a radial direction. In addition, a connector is known that further includes a means for holding a retainer in a temporary engagement position in order to prevent the retainer from unintentionally moving to a regular engagement position, and a means for detecting insertion of a pipe, and this connector is disclosed in Japanese Laid-Open Patent Publication No. 2004-125130.
A structure of the connector according to the aforementioned Japanese Laid-Open Patent Publication No. 2004-125130 will be described in reference to FIG. 19. A lock portion for engaging with a connector body 62 and holding the retainer 60 in the temporary engagement position where a pipe can be inserted into and detached from the connector body and a regular engagement position where the retainer 60 engages with the pipe and holds the pipe in non-detachable condition is formed on the retainer 60 at an opposite side to the bearing portion 61. However, when the lock at the temporary engagement position is released, the pivot movement toward an opposite side to the regular engagement position, that is, in a direction away from the connector body 62, is allowed. When the retainer 60 pivots to a certain position, an outer circumferential surface 63 of the retainer contacts with an outer circumferential surface of the connector body 62, and thus further pivot movement is stopped once (a condition in FIG. 19).
However, in the case of the known connectors, when a strong external force in a distancing direction is applied onto the retainer 60 or a torsional force is applied onto the retainer 60 in the contact position with this outer circumferential surface, there is a risk that the opening of the bearing portion expands and is removed from the pivot shaft 65.